Democrats in the U.S. Senate gave a solid thumbs down to President Donald Trump's announcement that he is likely to choose retired Sen. Joe Lieberman to replace former FBI Director James Comey.

According to Politico, if Trump thought that Lieberman would be a choice welcomed by Democrats, he got it squarely wrong. Lieberman is not popular among his former Senate colleagues. From a series of policy defections on key issues to Lieberman's decision to run as an independent in Connecticut after he lost the Democratic primary to challenger Ned Lamont in 2006, the former senator made many enemies among his own caucus.

Furthermore, critics of Trump's decision stress that the role of FBI director should be filled by someone who isn't a politician. Lieberman was Al Gore's vice presidential running mate in 2000 and ran for president himself in 2004.

“I don’t think there's going to be much excitement about that from our side of the aisle. Not because we don’t respect Joe Lieberman. But we need a law enforcement professional, not someone who’s run for office before,” said Sen. Claire McCaskill (D-MO) to Politico. “We don’t need anyone who’s put on a red shirt or blue shirt. Or who’s campaigned for president.”

“He has a history of angering Democrats and Republicans, which is probably a good experience for being FBI director. But my concern is about someone with a political background. This is a moment for someone with a law enforcement background,” said Sen. Chris Murphy (D-CT) -- currently the senator in Lieberman’s old seat. “It’s really important to restore people’s faith in the FBI.”

Lieberman lobbied from retirement to undermine former President Barack Obama's nuclear deal with Iran and is known for his close alliance with members of the Republican caucus like Sens. John McCain (R-AZ) and Lindsey Graham (R-SC).

Also, some Democrats are skeptical about Lieberman's independence from Trump given that the two are currently in an attorney-client relationship.

“Joe Lieberman has no real law enforcement credentials. Look where he works now, a Trump law firm. That tells me a lot,” said Sen. Sherrod Brown (D-OH).

Brown is one of the many Democrats who blames Lieberman for lobbying with Republicans against a 2009 Democratic proposal to extend Medicare benefits to people 55 years old rather than the current lower limit of 65.

"He’s the reason we lost Medicare at 55," Brown told Politico. "Couldn’t have had anything to do with the insurance industry lobbying in Hartford. I’m sure Lieberman couldn’t succumb to that.”